JP2023163911A - Surface coating composition, surface coating member, and construction method - Google Patents

Abstract

To provide a surface coating composition excellent in corrosion resistance.SOLUTION: A surface coating composition of the present invention includes: zinc powder; a silane compound; an organic metallic compound containing one kind or two or more kinds selected from the group consisting of a titanium element, a zirconium element, and an aluminum element; and a solvent.SELECTED DRAWING: Figure 1

Description

The present invention relates to a surface coating composition, a surface coating member, and a construction method.

Until now, various developments have been made in paints and surface treatment agents that protect substrates. As this type of technology, for example, the technology described in Patent Document 1 is known. Patent Document 1 describes a painting technique that forms a base coating film of zinc-rich paint on the surface of steel materials (Claim 1, Paragraph 0001, etc.)

Japanese Patent Application Publication No. 2016-040350

As a result of studies conducted by the present inventor, it has been found that there is room for improvement in terms of corrosion resistance in the coating technique of Patent Document 1.

However, when zinc-rich paint is applied to steel and used in salt-damaged areas near the ocean or the bay, corrosion progresses faster due to the influence of the external environment containing salt such as water and sea salt particles. It was found that no anticorrosion effect could be obtained.

Based on these findings, the present inventors conducted further intensive research and found that a zinc-silicon containing coating was applied to the surface of a metal substrate by using a zinc-silicon containing paint containing a silane compound and an organometallic compound together with zinc powder. The present inventors have discovered that the corrosion resistance of a metal base material can be improved even when exposed to water, salt, etc. by protecting the metal base material, and the present invention has been completed.

According to one aspect of the present invention, a surface coating composition, a surface coating member, and a construction method are provided.
1. zinc powder and
a silane compound;
an organometallic compound containing one or more selected from the group consisting of titanium element, zirconium element, and aluminum element;
a solvent;
A surface coating composition comprising:
2. 1. The surface coating composition according to
A surface coating composition in which the content ratio Si/Zn of silicon element to zinc element contained in the surface coating composition is 0.05% by mass or more and 20% by mass or less.
3. 1. Or 2. The surface coating composition according to
A surface coating composition, wherein the zinc powder contains zinc particles having a particle size of 1 μm to 10 μm.
4. 1. ~3. The surface coating composition according to any one of
A surface coating composition, wherein the content of zinc element in a dry film made of the surface coating composition is 50% by mass or more.
5. 1. ~4. The surface coating composition according to any one of
A surface coating composition containing an inorganic or organic binder.
6. 1. ~5. The surface coating composition according to any one of
A surface coating composition that is substantially free of elemental chromium.
7. 1. ~6. The surface coating composition according to any one of
A surface coating composition, wherein the silane compound contains a silane coupling agent and/or an alkoxysilane.
8. 1. ~7. The surface coating composition according to any one of
A surface coating composition, wherein the solvent contains an alcohol.
9. base material and
A zinc-silicon containing film formed on the base material,
The zinc-silicon containing film comprises: 1. ~8. A surface coating member comprising a dry film made of the surface coating composition according to any one of the above.
10. mixing a zinc-containing paint and a silicon-containing paint to prepare a surface coating composition;
The step of applying the obtained surface coating composition to the surface of the substrate and drying it to form a zinc-silicon containing film,
The zinc-containing paint includes zinc powder,
The silicon-containing paint contains a silane compound, an organometallic compound containing one or more selected from the group consisting of a titanium element, a zirconium element, and an aluminum element, and a solvent.
Construction method.

According to the present invention, a surface coating composition with excellent corrosion resistance, a surface coating member using the same, and a construction method are provided.

FIG. 1 is a cross-sectional view schematically showing an example of the configuration of a surface covering member according to the present embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that in all the drawings, similar components are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate. Furthermore, the figure is a schematic diagram and does not correspond to the actual dimensional ratio.

The outline of the surface coating composition of this embodiment will be explained.

The surface coating composition of the present embodiment includes zinc powder, a silane compound, an organometallic compound containing one or more selected from the group consisting of titanium element, zirconium element, and aluminum element, and a solvent. include.

According to the findings of the present inventors, by coating the surface of a metal base material with the above-mentioned surface coating composition, the progress of corrosion of the metal base material can be suppressed and the corrosion resistance of the metal base material can be improved. It was discovered that something could be done. It is expected that such anticorrosion effects will be sufficient even when used for a long time in salt-damaged areas near the ocean or the bay.

Although the detailed mechanism is not clear, it is inferred as follows.
Normally, some of the zinc in the zinc-rich film formed by applying zinc-rich paint reacts with metals such as iron at the interface of metal parts, dissolves (ionizes), and produces corrosion products (zinc oxide film). generate. Since this corrosion product does not conduct, it becomes difficult to obtain a corrosion protection effect against corrosion factors such as chloride ions.
On the other hand, in this embodiment, part or all of the surface of the metal substrate is coated with a dry film obtained by drying the surface coating composition, that is, a zinc-silicon containing film. This film contains a zinc portion containing zinc and a silicon portion containing a reactant of a silica compound or an organometallic compound. Then, the silanol group (-Si-OH) reacts with Zn and the silicon part is present on the surface of the zinc part (zinc particles), so that excessive dissolution of zinc in the zinc part is suppressed. This makes it possible to suppress excessive generation of corrosion products generated by dissolution of zinc, so that a sufficient corrosion prevention effect against the above-mentioned corrosion factors can be obtained. Moreover, the silicon portion can suppress the permeation of chloride ions in the film.
Since the surface coating composition can exhibit such an ability to suppress zinc dissolution and an ability to block permeation of chloride ions, it is presumed that the corrosion resistance of the metal base material can be highly improved.
In addition, in the surface coating composition of this embodiment, since the Zn component and the Si component are well dispersed, the Zn component and the Si component are uniformly present in the thickness direction of the zinc-silicon containing film to be formed. Therefore, it becomes possible to reduce the above-mentioned variation in quality of corrosion resistance.

The construction method of this embodiment includes the steps of preparing the above-mentioned surface coating composition, and applying the obtained surface coating composition to the surface of the above-mentioned base material and drying it to form a zinc-silicon containing film. and, including.
A surface-coated member can be obtained by such a construction method.

One example of preparing a surface coating composition may include, but is not limited to, mixing a zinc-containing paint that includes zinc powder and a silicon-containing paint that includes a silane compound, an organometallic compound, and a solvent. Not done.

According to the construction method of this embodiment, compared to the case where the zinc-containing paint and the silicon-containing paint are individually overcoated, there is no need for time for the base to dry, so the construction time can be significantly shortened. This can also reduce construction costs.

Note that each component in the zinc-containing paint and each component in the silicon-containing paint can be mixed in any order.

As the coating method, a known method can be employed, and examples thereof include a method of dipping the substrate, a method of using a spin coater, a method of spraying, a method of coating with a brush roller or a roller, and the like.
Note that the number of times of application may be one, or two or more times. The number of times of application can be appropriately set depending on the desired coating film thickness.
The drying method may be performed at room temperature, or may be performed by heating to an appropriate temperature.

The surface coating member of this embodiment includes a base material and a zinc-silicon containing film formed on the base material. This zinc-silicon containing coating is comprised of a dry film of the surface coating composition described above.

The base material of the surface covering member is selected from the group consisting of, for example, a metal base material, a wood base material, and a stone base material. In addition, a concrete base material or a ceramic base material may be used.

By coating with the surface coating composition of this embodiment, it is possible to suppress deterioration of the base material. One way to suppress base material deterioration is to suppress a decrease in corrosion resistance of a metal base material. In addition, one way to suppress deterioration of base materials is to suppress changes in color tone of various base materials such as wood base materials and stone base materials.

Examples of the metal material constituting the metal base material include Al-based materials, Fe-based materials, Ni-based materials, Co-based materials, and the like. These may be used alone or in combination of two or more.
As the Fe-based material, various steel materials and iron-based alloys can be used, such as carbon steel, alloy steel, nickel chromium steel, nickel chromium molybdenum steel, chromium steel, chromium molybdenum steel, manganese steel, tool steel, Examples include stainless steel, heat-resistant steel, nitrided steel, and case hardened steel.

The lower limit of the thickness of the zinc-silicon containing film is, for example, 30 μm or more, preferably 40 μm or more, and more preferably 50 μm or more. Thereby, the effect of corrosion resistance can be fully exhibited.
On the other hand, the upper limit of the thickness of the zinc-silicon containing film is not particularly limited, but may be 300 μm or less, or 200 μm or less.
The thickness of the zinc-silicon-containing film is the dry thickness of the coating film formed by applying the surface coating composition.

The surface covering member of this embodiment can be used for various purposes, such as civil engineering structures, architectural structures, power/communication structures, marine/fishery structures, railway/transportation/road structures, It is used to form part or all of agricultural and horticultural structures, environmental sanitation structures, etc.

Civil engineering structures such as bridge supports, overpasses, plated bridges, gratings, reinforcing bars, seismic reinforcement, plating materials for civil engineering, and architectural structures such as steel pipes for electricity, gas, water, etc., net supports for golf courses, stadium pillars, and buildings. - House steel columns and beams, temporary scaffolding, handrails, safety fences, external stairs, various frames, iron sashes, multi-story parking lots, lightning rods, seismic reinforcement, power and communication structures, steel towers, steel columns, panza masts, power equipment. Frames, insulator metal fittings, various antennas, transformer hangers, transformers, structures for ships and fishing, refrigeration facilities, anchors, chains, fishing lights, buoys, oil tanks, various fitting hardware, piping hardware, structures for railways, transportation, and roads. As soundproof walls, overhead wire structures, power transmission towers, lighting poles, guardrails, sign posts, fences, rails, agricultural and horticultural structures, greenhouses, silos, poultry houses, agricultural assembly structures, irrigation pipes, agricultural machinery, Examples of vinyl greenhouses and environmental sanitation structures include environmental sanitation equipment, incinerators, and the external surfaces of various tanks.
Among these, it is preferable that a structure provided in the ocean, near the outside of the ocean, or near a bay, a so-called ocean/bay structure, is provided with the above-mentioned surface covering member.

The surface-coated member of this embodiment may be configured such that the zinc-silicon-containing film does not substantially contain a chromium component. As a result, the environmental load can be reduced, so that the surface covering member can be suitably applied to a structure exposed to the external environment.

FIG. 1 is a cross-sectional view showing an example of the configuration of the surface covering member 100.
The surface coating member 100 in FIG. 1 includes a base material 10 and a zinc-silicon containing film 20 formed on the surface of the base material 10.

Note that the surface coating member 100 may have a single layer or multiple layers of other coatings on the surface of the zinc-silicon containing coating 20 depending on the purpose.
As the other coating film, known coatings such as colored coatings, metallic coatings, clear coatings, color clear coatings, and epoxy coatings can be used.

Hereinafter, the composition components of the surface coating composition of this embodiment will be explained in detail.

The surface coating composition includes at least zinc powder, a silane compound, an organometallic compound, and a solvent.
In addition, the surface coating composition is selected from the group consisting of a binder component, aqueous colloidal silica, a water-dispersible resin, a solvent such as a first solvent and a second solvent, and an additive such as a first additive and a second additive. may include one or more.

When the content ratio of silicon element to zinc element contained in the surface coating composition is defined as Si/Zn, Si/Zn is configured to be within a range of, for example, 0.05% by mass or more and 20% by mass or less. may be done.
The lower limit of Si/Zn is, for example, 0.05% by mass or more, preferably 0.1% by mass or more, and more preferably 0.14% by mass or more. This makes it possible to suppress excessive dissolution of zinc, thereby further improving corrosion resistance.
The upper limit of Si/Zn is, for example, 20% by mass or less, preferably 10% by mass or less, and more preferably 2% by mass or less. Thereby, the ability to inhibit zinc dissolution can be appropriately controlled, so that corrosion resistance can be further improved.

The lower limit of the content of the zinc element in the dry film made of the surface coating composition is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, and even more preferably 80% by weight or more. . Thereby, base material protection ability such as sacrificial corrosion resistance can be enhanced.
On the other hand, the upper limit of the content of zinc element in the dry film is not particularly limited, but may be, for example, 96% by weight or less, 95% by weight or less, or 90% by weight or less. Thereby, corrosion resistance in environments containing water and salt can be further improved.

An example of the surface coating composition may be one obtained by mixing a zinc-containing paint described below and a silicon-containing paint described below.

The above-mentioned zinc-containing paint contains at least zinc powder, and may also contain one or more selected from the group consisting of a binder component, a first solvent, and a first additive.

<Zinc powder>
The zinc powder may comprise zinc particles having an average particle size of, for example, 1 μm to 10 μm, preferably 3 μm to 7 μm.

<Binder component>
Examples of the binder component include inorganic binders and organic binders.
Examples of the inorganic binder include alkyl silicates, alkali silicates, and the like.
Examples of organic binders include acrylic compounds, epoxy compounds, urethane compounds, and the like.
These may be used alone or in combination of two or more.

Examples of the first solvent include water, organic solvents, and the like.

A zinc-containing paint in which the first solvent mainly contains an organic solvent is referred to as a solvent-based zinc-containing paint, and a zinc-containing paint in which the first solvent mainly contains water is referred to as a water-based zinc-containing paint.
As the solvent-based zinc-containing paint, for example, "ROVAL", "EPOLOVAL", "ROVAL Silver", "ROVAL Alpha", etc. manufactured by ROVAL may be used. As the water-based zinc-containing paint, for example, "Water-based ROVAL" manufactured by ROVAL Co., Ltd. may be used.

These solvent-based zinc-containing paints and water-based zinc-containing paints may contain, for example, pigments, thickeners, antifoaming agents, dispersants, rust preventives, etc. as first additives. The first additive may be used alone or in combination of two or more.

The silicon-containing paint contains at least a silane compound and an organometallic compound, and contains one or more selected from the group consisting of aqueous colloidal silica, a water-dispersible resin, a second solvent, and a second additive. It's okay.

Each component contained in the silicon-containing paint undergoes various crosslinking reactions, spatial arrangements, and/or dispersions in the silicon portion of the zinc-silicon-containing coating. In the silicon part, the solvent such as the second solvent is removed by drying, but it is allowed that it remains unavoidably.

Although the detailed mechanism of the structure of the silicon portion is not clear, it is assumed as follows.
A silane coupling agent and/or a silane compound such as an alkoxysilane has a silicon moiety having a two-dimensional structure and/or three-dimensional cross-linked structure due to a cross-linking reaction such as hydrolysis condensation, etc., in which the silyl group contained in the molecule is formed. Can be formed.
A silicon portion having a crosslinked structure is formed by a dehydration condensation reaction between a hydrolyzed condensate of a silane compound and an organometallic compound. For example, a crosslinked structure between a silicon atom derived from a silane compound and a transition metal atom derived from an organometallic compound via an oxygen atom is formed in the silicon portion. Furthermore, the organometallic compound can promote chemical bonding with the silane compound or other components contained therein, thereby forming a silicon portion with high strength.
In addition, silicon atoms derived from silane compounds and metal atoms of organometallic compounds can be chemically bonded to the zinc moiety via oxygen atoms, and the silicon moiety can be physically bonded to the base material (metal base material). . This improves the adhesion between the film containing the silicon portion and the base material.
Further, since inorganic particles such as silica having an appropriate particle size are appropriately arranged in the void space in such a silicon part, a highly dense silicon part can be obtained. A chemical bond can be formed with the silicon atom of the silane compound in the crosslinked structure on the surface of the inorganic particles such as silica through oxygen atoms.

<Silane compound>
The silane compound includes one or more selected from the group consisting of a silane coupling agent and an alkoxysilane.

As the silane coupling agent, a silane compound in which a hydrolyzable group such as an alkoxy group and a reactive functional group are bonded to a silicon atom is used. As the silane coupling agent, one or both of monomers and oligomers may be used.
By using a silane coupling agent, it can be stabilized as an aqueous solution. It is believed that the silane coupling agent can improve the affinity between components such as aqueous colloidal silica, thereby making it possible to form a stable aqueous solution (composition).

As the silane coupling agent, a water-soluble silane coupling agent that can be dissolved in water is preferred.
The water-soluble silane coupling agent may include, for example, a silane coupling agent having an epoxy group as a functional group (epoxy silane), or a silane coupling agent having an amino group as a functional group (amino silane). Among these, it is more preferable to use epoxy silane from the viewpoint of corrosion resistance.

Examples of the epoxysilane include glycidyl or epoxy group-containing trimethoxysilane, such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 2-(3,4-epoxycyclohexylethyl)trimethoxysilane. Examples include alkoxysilane compounds.

As the alkoxysilane, a silane compound in which an alkoxy group is bonded to a silicon atom and a non-reactive functional group such as a hydrogen group or an alkyl group is bonded can be used, for example, an alkyl alkoxysilane can be used. As the alkoxysilane, one or both of monomers and oligomers may be used.
As the alkyl alkoxysilane monomer, for example, at least one selected from methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, vinyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane can be used.

The content of the silane coupling agent and/or alkoxysilane in the silicon-containing paint is, for example, 0.1% by mass to 12% by mass, preferably 1% by mass to 11% by mass, more preferably is 1.5% by mass to 10% by mass.

In this specification, "~" indicates that the upper limit value and the lower limit value are included, unless otherwise specified.
Moreover, the solid content refers to the remainder after removing volatile components such as water and alcohol solvents. This solid content may be a residue remaining after the reaction of each component after heat-treating the silicon-containing paint.

<Organometallic compound>
The organometallic compound includes one or more selected from the group consisting of organotitanium compounds, organozirconium compounds, and organoaluminum compounds.

Examples of organic titanium compounds include titanium chelates, titanium alkoxides, titanium acylates, and the like. Examples of the organic zirconium compound include zirconium chelate, zirconium alkoxide, zirconium acylate, and the like. Examples of organoaluminum compounds include aluminum chelates, aluminum alkoxides, and the like. These may be used alone or in combination of two or more.
Further, as the organometallic compound, either a monomer or an oligomer or both may be used.

The organic titanium compound is, for example, 0.01% to 7% by mass, preferably 0.015% to 5% by mass, more preferably 0.02% by mass in terms of solid content in the entire silicon-containing paint. It is 3% by mass.

<Aqueous colloidal silica>

Water-soluble colloidal silica is dispersed in an aqueous solvent or a mixed solvent containing water, and includes inorganic particles composed of SiO ₂ . The average particle diameter of the inorganic particles may be, for example, 1 to 200 nm.

In addition to aqueous colloidal silica, inorganic colloid particles made of inorganic oxides such as Al ₂ O ₃ , ZrO ₂ , and Fe ₂ O ₃ may be included. Inorganic colloid particles are composed of inorganic particles dispersed in water.

By using water-based colloidal silica, the strength of the film can be further improved. Further, since the dispersibility in the composition can be improved, a film can be formed in which the silica particles are uniformly dispersed in the film.

The content of the aqueous colloidal silica in the silicon-containing paint is, in terms of solid content, for example, 0.5% by mass to 12% by mass, preferably 0.6% by mass to 10% by mass, more preferably 0.8% by mass. It is from 8% to 8% by mass. By setting it to the above lower limit or more, appropriate strength can be imparted to the film. By setting it below the above upper limit, the physical properties of the film can be balanced.

<Water dispersible resin>
Water-dispersible resins are comprised of resins that are dispersed in water.
In addition to the water-dispersible resin, a water-soluble resin may also be included. Water-soluble resins are comprised of resins that dissolve in water.

The resin constituting the water-dispersible resin or water-soluble resin may be appropriately selected from resins that can be dispersed in water, such as polyacrylic acid resin, silicone resin, phenol resin, epoxy resin, polyurethane resin, and polyester resin. , polyvinyl butyral resin, phenol resin, and modified products thereof. These may be used alone or in combination of two or more.
Among these, polyacrylic acid resin, epoxy resin, polyurethane resin, silicone resin, etc. may be used as the water-dispersible resin from the viewpoint of corrosion resistance and film durability.

The content of the water-dispersible resin in the silicon-containing paint is, for example, 1% by mass to 12% by mass, preferably 1.5% by mass to 11% by mass, more preferably 2% by mass to 10% by mass. %. By setting the above lower limit or more, the heat resistance and corrosion resistance of the film can be improved. By setting it below the above upper limit, the physical properties of the film can be balanced.
Note that the content of the water-soluble resin can be within the same range as the content of the water-dispersible resin.

The second solvent may be composed of an aqueous solvent containing only water, or may be composed of an aqueous mixed solvent containing water and a hydrophilic solvent other than water.

Examples of the water include city water, distilled water, ion exchange water, and the like.

Examples of the hydrophilic solvent include polar organic solvents such as alcohol. From the viewpoint of solution stability, the aqueous mixed solvent may be composed of a mixed solvent of water and alcohol. The content ratio of water in the aqueous mixed solvent can be determined in consideration of the chemical properties and blending amounts of each component in the silicon-containing paint.
By using alcohol, the solubility of each component can be improved, and the storage stability of the resulting silicon-containing paint can be improved.

Examples of the alcohol include low-boiling alcohols with a boiling point of less than 100°C such as methanol, ethanol, n-propyl alcohol, and iso-propyl alcohol, and iso-butanol, methyl cellosolve, ethyl cellosolve, and propylene glycol monomethyl ether (PGME). , butyl cellosolve, ethylene glycol monotertiary butyl ether (ETB), diformaldehyde methoxyethanol, and other high boiling point alcohols having a boiling point of 100° C. or higher can be used. These may be used alone or in combination of two or more.

As the second additive, various additives normally included in the primer material can be used, such as rust preventives, pH adjusters, lubricants, preservatives, fillers, colorants, surfactants, erasers, etc. Examples include foaming agents, leveling agents, and antibacterial agents. These may be used alone or in combination of two or more. The amount of the additive added can be appropriately set depending on the application.

As the above-mentioned rust preventive agent, for example, a phosphoric acid-based rust preventive agent or the like is used.
Examples of the preservative include isothiazoline compounds.

As an example of a silicon-containing paint (aqueous antirust treatment agent), all components contained in the composition may be composed of water-soluble components or water-dispersible components. That is, the silicon-containing paint may be composed of an aqueous solution containing only water-soluble components or water-dispersible components.

As the silicon-containing paint, for example, "ZEC-888" series, "ZEC-W" series, etc. manufactured by Discharge Precision Machining Research Institute may be used.

The surface coating composition may be a chromium-free antirust treatment agent that does not substantially contain chromium elements such as hexavalent chromium and trivalent chromium.

In addition, in this specification, "substantially not containing chromium element" means that the amount of hexavalent chromium and trivalent chromium is 0.1% by mass or less. The amounts of hexavalent chromium and trivalent chromium refer to the content of chromium salts having this specific valence.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and the present invention includes modifications, improvements, etc. within a range that can achieve the purpose of the present invention.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the description of these Examples.

<Adjustment of zinc-containing paint>
・Zinc-containing paint 1:
Zinc powder and ethyl silicate solution (ethyl silicate, ethanol, methanol) were mixed to obtain zinc-containing paint 1. The content of zinc element in the dry film of zinc-containing paint 1 was 84% by weight.

・Zinc-containing paint 2:
A zinc-containing paint 2 was obtained by mixing zinc powder, an acrylic compound, and an organic solvent. The content of zinc element in the dried film of zinc-containing paint 2 was 96% by weight.

・Zinc-containing paint 3:
Zinc powder, urethane compound, and water were mixed to obtain zinc-containing paint 3. The content of zinc element in the dry film of zinc-containing paint 3 was 93% by weight.

<Preparation of silicon-containing paint>
・Silicon-containing paint 1:
A mixture of 250 parts by weight of ethyl silicate 40 (manufactured by Tama Chemical Industries, Ltd.), 5 parts by weight of vinyltrimethoxysilane (manufactured by Toray Dow Corning, SH6300) and about 65 parts by weight of isopropyl alcohol as raw materials for alkoxysilane is mixed with 1N Acidic water prepared by mixing 4 parts by weight of hydrochloric acid and 27 parts by weight of water was added thereto, and the mixture was kept at 35° C. for 24 hours with stirring to cause alkoxysilane condensation polymerization to obtain an oligomer solution of alkoxysilane.
25 parts by weight of the obtained alkoxysilane oligomer solution, 3 parts by weight of an organometallic compound (titanium chelating agent: titanium lactate ammonium salt, manufactured by Matsumoto Fine Chemical Co., Ltd., TC-200), 36 parts by weight of n-propyl alcohol, ethylene glycol tertiary butyl ether. 16 parts by weight, 20 parts by weight of propylene glycol monomethyl ether, 0.3 parts by weight of a silane coupling agent (epoxysilane: 3-glycidoxypropyltriethoxysilane, manufactured by Asahi Kasei Wacker Silicone Co., Ltd., GF-82), and a stirrer. An aqueous solution (silicon-containing paint 1) was obtained.

・Silicon-containing paint 2:
Silane coupling agent (epoxysilane: 3-glycidoxypropyltriethoxysilane, Asahi Kasei Wacker Silicone Co., Ltd., GF-82) 3 parts by weight, water-dispersible resin (water-dispersible urethane resin, Lubrizol Co., Ltd.) 8 parts by weight Part by weight, 0.5 part by weight of organometallic compound (titanium chelating agent: titanium lactate ammonium salt, manufactured by Matsumoto Fine Chemical Co., Ltd., TC-300), inorganic particles (aqueous colloidal silica, manufactured by Nissan Chemical Industries, Ltd., Snowtex ST-O, 8 parts by weight of acidic sol (particle size: 20 nm), 80 parts by weight of ion-exchanged water, and 1 part by weight of isopropyl alcohol were mixed using a stirrer to obtain an aqueous solution (silicon-containing paint 2).
The content of the above-mentioned non-solvent components (silane coupling agent, water-dispersible resin, organometallic compound, inorganic particles) represents the amount used.

<Preparation of base material>
・Base material 1: Grit-blasted steel plate (JIS G 3101) of general structural rolled steel (SS400)
・Base material 2: Cold rolled steel plate ・Dull finish (SPCC-SD) (JIS G 3141)

<Adjustment of surface coating composition>
(Comparative Examples 1 to 3)
The above zinc-containing paints 1 to 3 were used as they were as surface coating compositions 1 to 3 in Comparative Examples 1 to 3.

(Example 1)
Surface coating composition 4 was prepared by mixing the zinc-containing paint 1 and the silicon-containing paint 1 at a weight ratio of 95:5.
(Example 2)
Surface coating composition 5 was prepared by mixing the zinc-containing paint 1 and the silicon-containing paint 1 at a weight ratio of 90:10.
(Example 3)
Surface coating composition 6 was prepared by mixing the zinc-containing paint 2 and the silicon-containing paint 1 at a weight ratio of 95:5.
(Example 4)
Surface coating composition 7 was prepared by mixing the zinc-containing paint 2 and the silicon-containing paint 1 at a weight ratio of 90:10.
(Example 5)
A surface coating composition 8 was prepared by mixing the zinc-containing paint 3 and the silicon-containing paint 2 at a weight ratio of 95:5.
(Example 6)
Surface coating composition 9 was prepared by mixing the zinc-containing paint 3 and the silicon-containing paint 2 at a weight ratio of 90:10.

The content ratios Si/Zn of silicon element to zinc element contained in the obtained surface coating compositions 4 to 9 were 0.32% by weight, 0.67% by weight, 0.31% by weight, and 0.3% by weight, respectively. They were 65% by weight, 0.14% by weight, and 0.29% by weight.
Regarding the obtained surface coating compositions 4 to 9, the zinc element content in the dry film was measured according to JIS K5553 Type 1, and was 82.9% by weight, 81.7% by weight, and 94.7% by weight, respectively. %, 93.3% by weight, 91.8% by weight, and 90.6% by weight.

<Preparation of surface coating member>
The obtained surface coating composition 1 was spray-coated and dried at room temperature twice on the prepared substrate 1 to form a film of about 80 μm, and sample 1 (surface coating member) was obtained.

Samples 2 to 9 below were prepared in the same manner as in the preparation of the surface-coated member described above.
- Samples 2 to 9: Using base material 1, each of the above surface coating compositions 2 to 9 was applied twice.

Using the obtained surface coated member, the following evaluation items were evaluated.

<Combined cycle test: CCT test>
Using the obtained surface coating members of Samples 4 to 9 of Examples and surface coating compositions of Samples 1 to 3 of Comparative Examples, a cross cut was made until it reached the surface of the substrate, and in accordance with JASO M 609, A combined cycle test (1 cycle of 8 hours of salt water spraying at 35°C for 2 hours → drying at 60°C for 4 hours → moistening at 50°C for 2 hours) was carried out from 72 hours to 288 hours. The cycle time (h) was measured when no abnormality occurred in the coating film. Furthermore, the ability to inhibit zinc dissolution was determined based on the occurrence of white rust.

It was confirmed that the cycle time of samples 4 to 9 of the example was 2 to 2.5 times longer than that of the corresponding samples 1 to 3 of the comparative example. As described above, the surface-coated members of each Example showed results that, compared to the Comparative Example, the effect of preventing base material deterioration, such as excellent corrosion resistance, was obtained.
Note that similar results were obtained even when substrate 2 was used instead of substrate 1.

10 Base material 20 Zinc-silicon containing film 100 Surface coating member

Claims (10)

zinc powder and
a silane compound;
an organometallic compound containing one or more selected from the group consisting of titanium element, zirconium element, and aluminum element;
a solvent;
A surface coating composition comprising: The surface coating composition according to claim 1, comprising:
A surface coating composition in which the content ratio Si/Zn of silicon element to zinc element contained in the surface coating composition is 0.05% by mass or more and 20% by mass or less. The surface coating composition according to claim 1, comprising:
A surface coating composition, wherein the zinc powder contains zinc particles having a particle size of 1 μm to 10 μm. The surface coating composition according to claim 1, comprising:
A surface coating composition, wherein the content of zinc element in a dry film made of the surface coating composition is 50% by mass or more. The surface coating composition according to claim 1, comprising:
A surface coating composition containing an inorganic or organic binder. The surface coating composition according to claim 1, comprising:
A surface coating composition that is substantially free of elemental chromium. The surface coating composition according to claim 1, comprising:
A surface coating composition, wherein the silane compound contains a silane coupling agent and/or an alkoxysilane. The surface coating composition according to claim 1, comprising:
A surface coating composition, wherein the solvent contains an alcohol. base material and
A zinc-silicon containing film formed on the base material,
A surface-coated member, wherein the zinc-silicon-containing film is a dry film made of the surface-coating composition according to any one of claims 1 to 8. mixing a zinc-containing paint and a silicon-containing paint to prepare a surface coating composition;
The step of applying the obtained surface coating composition to the surface of the substrate and drying it to form a zinc-silicon containing film,
The zinc-containing paint includes zinc powder,
The silicon-containing paint contains a silane compound, an organometallic compound containing one or more selected from the group consisting of a titanium element, a zirconium element, and an aluminum element, and a solvent.
Construction method.

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